Gun perforator



All@ 17, 1943- l.. SPENCER 2,327,141.

RRRRRRRRRRR OR INVENTOR Patented ug.. 17, 1943 GUN BERFORATOR LloydSpencer, Los Angeles, Calif., assigner to Lane-Wells Company, Los corporation of Delaware Angeles, Calif., a

Application september 2s, 1942, serial No. 459,461

" 1o Claims. (ci. lei-0.5)

My invention relates'te gun perforators; that is, to devices designed to nre bullets through well casing for the purpose of opening the casing vof my Y' l to surrounding fluid. Among the objects invention are:

`First,` to provide a gun perforatorl which utilizes the concussion or pressure wave occurring in the medium in which the gun perforator is immersed, incidental 'to discharge of one gun unit to re 'adjacent gun units;

Second, to provide a gun pe'rforator wherein the detonator and its iiring means is located between the bullet and cartridge of each gun unit and the'bullet is exposed to :uid pressure' and is therefore capable of driving backwardly to set oi! the corresponding detonator when.sub'

iected to excessive pressure applied through the muzzle of the gun bore; v

Third, to provide a gun perforator which may 1 be so arranged that it must b'e submerged in liquid to provide amedium to transmit a concussion or pressure wave of suiilcient force from one unit to another, thereby providing a detonator type gun perforator which is relatively safe to handle:

Fourth, to provide a multiple unit 'gun perforator whereby all 'intercommunicating passages or wire conduits betweenvthe several gun units are eliminated, thereby providing a gun perforator which is particularly simple and economical of manufacture; Fifth, to provide a multiple unitgun perforator which is inherently so arranged that the gun bores may be closely 'spaced and occupy a maximum proportion of the gun perforators diameter,thereby providing a gun perforator of minimum Weight andv maximum firing power;

Sixth, to provide. a gun perforatorthe operation of which may be initiated by any of the conventional gun ring means, that-is, the gun perforator may be suspended from a conductor core cable and initially fired electrically or lowered on a wire line and fired mechanically by means of a go-devil or analogous devices: and

Seventh, to provide a gun perforator which may comprise a plurality of interchangeable gun sections, each incorporating a. plurality of gun units, the ygun sections being arranged to be connected end t0 end and as many sections con- 50 nected ltogether as desired or as may be limited by the strength of the cable from which it is suspended, thereby providing a gun perforator that is capable of ring a large number of shots.Y

With the above and other objects in view, as

may appear hereinafter, reference 4is "directed to the accompanying drawing, in which:-

Figure 1 is a fragmentarylongitudinal elevational view of my gun 'perforatom' and` Figure 2 is an enlarged-typical transverse sectional view thereof taken through2-f2lof-3igl ure 1.

My gun perforator comprises agun body I in l v the form cfa cylindrical bar of metal having aninternally threaded socket at one end and an externally threaded pinv at the. other, so that the gun body may be joined `end to end with other gun bodies, as shown in Figure 1. gun body is provided with a plurality of laterally directed gun barrel sockets 2 which are internally threaded. At the inner'end of each socket 2 is a cartridge chamber 3 of .smaller diameter than -the socket and therefore forming thetewith .a

shoulder 4.

Each socket 2 receives a gun barrel-5 having' a central gun bore .6. I The inner or breech end of the gunbore 6 is beveled', as indicated by 1. Each gun'barrel receives a bullet 8.v A sealv disk 9 is Welded or Aotherwise secured to the base end of each bullet 8, or the bullet may merely restl thereagainst. 'I'he seal disk 9 comprisesal flange portion adapted yto be clamped betw'en the inner end of the gun barrel 5 and the shoul-v derl 4, and a conical portion I0. conforming to the beveled breech end 1 of the gun bore so as toform a structural member capable of Wlthstanding considerable load applied by'or through the bullet 8, but adapted to give way when a predetermined load is exceeded.l

Also clamped between the gun barre15 andA shoulder 4 isa detonator diskI I2. `'I'he'detonator disk I2 is atexcept for a small central recess I3vwhieh is.p erfo r'ated and-which receives a detonator I4.- 'I'he detonator may jbe similar tothe conventional detonator usdin the'car,

tridges emplyed in pistols andriiies. An ex.-

plosive cartridge I5 ts in the cartridge chamber 3.

' The een asi; a is provided with a. tip 1| which' may be reinforced by a corresponding tip latthe base'end of the bullet. The tip II is in registry with the detonator I4 so that-when the strength of `the'seal disk 9 is exceeded by pressure against the bullet, the bullet may be driven backwardly,

causing the ring tip 'tostrike the detonator and thereby set off the explosive cartridge.

The 'uppermost gun -body is connected to an ignition sub 2l which contains a cartridge 22l from which extends -a downwardly and outwardly directed blank bore 23 initially sealed by Each a seal disk 24. The ignition sub in turn is supported by a suitable ring head 3| adapted to re the cartridge 22 electrically or mechanically by conventional means.

The several sockets 2 in each gun body are preferably arranged so that they denne a spiral path along the gun body, as shown in Figure 1 and indicated by dotted lines in lFigure 2. The muzzle ends of the gun units are placed as close to each other as possible.

Operation of my gun perforator is as follows: f

It is preferred to operate the gun perforator under liquid. The seal disks 9 are made strong enough to resist the hydrostatic head of the liquid at the depth at which the .gun perforator is discharged, but are not strong enough to withstand the concussion created by the discharge of an adjacent gun unit or by discharge of the cartridge 22. Thus when the cartridge 22 is discharged the bullets of the adjacent gun units are driven Abackwardly against their respective detonators, setting oi their explosive cartridges. The concussion resulting froml the discharge of the first gun unit is suicient to' set off the gun units not affected directly by the discharge of the cartridge 22; these in turnire the next adjacent units until all of the gun units have red.

Theoretically, if the gun is immersed in a liquid which is relatively incompressible the discharge of the cartridge 22 would set off all of the gun units. Actually, however, gas may be .present in the liquid, the surrounding casing may expand slightly and air spaces exist behind the seal disk. All of these factors tend cumuiatively to reduce the effective-pressures as the distance between the cartridge 22 or discharging' gun vunits and the one to be fired increases. However, it is only necessary to create sufficient concussive force to set off two or three adjacent gun units as these in turn will create the necessary forcerto set 'oil' their neighbors.

The concussive force, or pressure wave incidental to discharge of a gun unit, materially exceeds the hydrostatic pressure'of the 'liquid in which the gun is immersed. At a distance embracing several, that is, three or four, of the. gun units shown in Figure 1the concussive pressure by al factor of at least two lor three at great depth in live" or gas-containing liquid and by a factor of as much as 100 atshallow,y depths. For'example, in, say, 50 feet of water the'concussive pressure is around 4000 to 5000 -pounds per square inch, while at 5,000 feet it is around 8,000 to 10,000 pounds per square'inch. Because of this Wide margin between concussive 'and hydrostatic pressures, it is relatively easy to select a seal disk capable of withstanding hydrostatic pressure, but adapted to giveway when subjected to the concussive pressure. Thus, in practice, the thickness of the seal disk is varied-according to the liquid depth at which it is desired to discharge the gun, or portions of the seal disk are weakened to accomplish the same effect, a half dozen sizes suiiicing for the range of ccnditions encountered.

It should be noted'that .immediately before a gun unit discharges its bullet is moving backward.' The kinetic energy of the backwardly moving bullet must be overcome before it starts forward under the explosive pressure generated by the cartridge. permitting increased generation ofpressure before forward movement of the bullet. Also, the effective length of the barrelv is increased as the bullet starts forward from a position in which This introduces a time. delay,

it protrudes partly from the rear end ef tha barrel.- Also, the rearward movement of the bul- -ferred to generally as the Mid-Continent area,

it is customary to bail the wellv 'virtually dry before shooting, so that,l much of the gun perforating done in this region' is in wells having a very low liquid head, -that is, a head of feet or so above the gun. This condition is obviously ideal for the operation of my'gun perforator, as indicated by the approximately 100 to 1 difference between the concussive and hydrostatic pressures. l l

While it is preferred and recommended, 'because' of the obvious safety advantages, to design the gun to re only under liquid it is. of course. obvious that the bullet may be so lightly retained that the relatively nominal pressure surge in air is suiicient for operation. This permits opera' tion of the gun perforator above the liquid level` should this be desired for any reason.

Various 'changes and alternate arrangements may be made within the scope of the appended claims, in which' it is my intention to claim4 a novelty .inherent in the invention.

I claim: A

1. A gun perforator comprising: means' delining a cartridge chamber and a gun bore vextending therefrom; a cartridge-for said lchamber; a bullet for said ygun bore; and a detonator interi posed between said cartridge and bullet.

'2. A gun perforator comprising: means dening a cartridgechamber and a gun bore extending therefrom; a cartridge for said chamber; a bullet for said gun bore; a. detonator interposed betweensaid cartridge and bullet adapted to be set off when said bullet is driven backwardly in said gun bore toward said cartridge; and means. initially restraining said bullet from ypressure contact with said detonator. said means adapted to give way when a predetermined inward pressure against the builet isexceeded.

3. A gun perforator comprising: a' plurality of gun units, each including means deflning a gun barrel and a cartridge chamber; bullets for said gun barrels; cartridges for said lcartridgechain bers; and detonators interposedl between said bullets and cartridge chambers; the muzzle ends of the gun bores of adjacent gun'units arranged in close proximity whereby the concussion incidental to the discharge -of oneI gun unit tends to'drive v the bullets of at least the adjacent gun yunits inwardlyagainst their respective detonators.

4. A gun perforator comprising: a plurality of gun units, each including'detonator and concussion responsive striker means; 'the-gun units beiing grouped in close proximity .to each' other whereby the concussion incidental to discharge Y,

of 'one gun unit actuates the striker means of at least theadjacent units to set of! their respective 0. detonators. A l

5. A gun perforator comprising: 'a plurality of i excluding liquid from said cartridges; the muzzle ends of the gun bores of adjacent gununits being arranged in close proximity whereby, when the gun units are submerged" in liquid, the con- Tiri;-

cussion incidental to the discharge of one gun unit causes the bullets of at least the adjacent gun units to be driven inwardly and cause coaction between their respective strikers and detonators.

6. A gun perforator comprising: a plurality of gun units, each including means defining a gun barrel and a cartridge chamber; bullets for said gun barrels; cartridges for said cartridge .cham-. bers; a exible fluid sealing and hydrostatic pressure resisting diaphragm; a detonator and a striker therefor interposed between said bullet and cartridge; the muzzle ends of the gun bores of adjacent gun units being arranged in close proximity whereby, when the gun units are submerged in liquid, the concussion incidental to the discharge of one gun unit in excess of the strength of said diaphragm causes the bullets of at least the adjacent gun units to be driven inwardly to cause coaction between their respective strikers and detonators.

7. A gun perforator comprising: a plurality 0f gun units, each including a detonator and a hydrostatic pressure-resistant, concussive pressure actuated firing means therefor vexposed to the pressure of the medium in which the gun units are immersed, said firing means of each gun unit being responsive to concussive pressures generated incidentally to the discharge of another gun unit.

8. A gun perforator comprising: a. plurality of gun units; a detonator for each gun unit; a hydrostatic pressure-resistant, concussive pressure responsive iiringmeans for each detonator, said ring means adapted to be immersed in liquid and susceptible to concussion incidental to discharge oian adiacent gun unit while under liquid.

9. A gun perforator comprising: a plurality of gun units, each having a gun bore and a cartridge Y chamber; a cartridge for said cartridge chamber; a detonator for said cartridge; and a pressure responsive means for each detonator, said means s being responsive to concussive pressures incidenf v ber; cartridges for said cartridge chambers; deton'ators for said cartridges; gun barrels having gun bores for said sockets; pressure responsive means secured in said socket by said gun barrels and positioned to engage said detonatorswhen gun barrels.

LLOYD SPENCER. 

